"The large carrier/access networks in the US" support Net Neutrality
Cable operators are not the most heavily invested in Internet infrastructure
Often difficult to classify what they are, as there aren't too many 'pure plays' left. For example the likes of Comcast would be as close as you get to a pure access cable operator, on the other hand the likes of Verizon are a cable, fiber & mobile operator and carrier all rolled into one. Hence my use of the generic term transmission provider, referring to anyone in the business of moving bits around, collectively these entities make up the core fabric of the Internet, after all, it is fundamentally a communication network, on top of which everything else is layered e.g. WWW and OTT content etc.
Bits on the internet are just bits. What about a large portion of internet traffic that's torrents?
Agreed, OTT, torrents, NNTP etc. are all similar in their impact, one which causes the US cable operators to behave the way they do, and coincidentally is root cause of a lot of the flak against SA ISPs on this forum. Again some background/context is required to understand why;
For Internet Access Services there are two broad classes of products offered;
(a) Dedicated/Business/Leased Line - this product offering is designed with a view that the service will be heavily utilised (saturated) most of the time, therefore the upstream infrastructure is expanded adequately to ensure additional dedicated capacity for each new link. Obviously this type of product is costed such that all the upstream capacity increases are recovered in the price, thus resulting in these products being quite pricey (at least for the man in the street).
(b) Shared/Broadband - this type of product offering takes advantage of the light/sporadic capacity demands of most consumers (when using applications like WWW and mail), allowing for upstream capacity to be shared. The price of these products factors in this sharing of network capacity/resources and thus results in them being far cheaper than (a).
Back to the issue at hand, when the mentioned applications (OTT, torrents, NNTP etc.) are used by a consumer, they result in capacity/resource demands on the network of (a), but only the income of (b). So from the operator's perspective this service is running at a loss. In the US case, the cable operators blame the OTT providers like Netflix for breaking the sharing balance on their network and are therefore are demanding compensation from them, otherwise they'll technically degrade the performance of the OTT's traffic to their broadband customers.
Locally this situation is similar for download applications like torrents and NNTP, but with these there is no central organisation to go demand compensation from, so they jump straight to the technical degradation solution, which we locally know as 'shaping'.